#while循环嵌套
i = 1
while i <= 5:
    j = 1
    while j <= i:
        print("*",end='')
        j += 1
    print(end="\n")
    i = i + 1

#for循环嵌套
for i in range(1, 6):
    for j in range(i):
        print("*",end='')
    print()

#3.4.3实例9 九九乘法表
for i in range(1, 10):
    for j in range(1, i + 1):
        #输出表达式
        print(str(j) + str("*") +str(i) + "=" + str(i * j), end="\t")
    print()